/Engine/Source/Editor/Sequencer/Public/ISequencerSection.h
Allows each section to have it's own unique widget for advanced editing functionality OnPaintSection will still be called if a widget is provided. OnPaintSection is still used for the background section display
The generated widget
virtual [TSharedRef](API\Runtime\Core\Templates\TSharedRef)< [SWidget](API\Runtime\SlateCore\Widgets\SWidget) > GenerateSectionWidget()